Improvement in wash-boards



' A. SMITH.

Wash-Board.

No. 203,786, Patented May 14, I878. V

WITNE E TTTTTTT Y UNITED STATES PATENT OFFICE.

MARK A. SMITH, OF EVANSVILLE, INDIANA.

IMPROVEMENT IN WASH-BOARDS.

Specification forming part of Letters Patent No. 203,786, dated May 14, 1878 application filed April 13, 1878.

To all whom it may concern:

Beit known that I, MARK A. SMITH, of Evansville, in the county of Vanderburg and State of Indiana, have invented certain new and useful Improvements in Wash-Board Rubbing-Plates and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, and to the letters and figures of reference marked thereon.

Figure 1 is a representation of a plan view of my improved wash-board and plate, and Fig. 2 is a transverse section of the same.

This invention has relation to improvements in wash-boards having a metallic rubbingplate attached to a suitable wooden back.

The nature of the invention consist in a metallic rubbing-plate having transverse rows of spiral corrugations, the directions of the spirals of the rows being alternately right and left handed, as more fully hereinafter shown and described.

In the annexed drawings, the letter A designates the frame, and B the rubbing-plate, of my improved wash-board, secured together in any suitable manner. The plate B, as shown in Fig. 1, has a number of rows of corrugations, a, extending from side to side thereof, and continuously from top to bottom of the same. These corrugations are arranged par allel to each other in positions oblique to the length of the rows. Theyare angular in crosssection, slightly S-shaped, and their crests or profiles are regularly convex. The corrugations in each row, taken together, present the appearance of a screw, the threads. of which are represented by the said corrugations. The spirals or twists of the rows of corrugations are alternately right and left handed-'- that is, if the top row is left-handed, the row next to it is right-handedthis alternation being continued to the bottom. The object of this is to prevent the article being rubbed from being carried against the side rail of the frame and injuring the knuckles of the operator.

What I claim as new, and desire to secure by Letters Patent, is-

The metallic rubbing-plate B, having transverse rows of spiral corrugations a, the directions of the spirals of the rows being alternately right and left handed, substantially as specified.

In testimony of which invention I have hereunto sct my hand this 6th day of May, in the year 1878.

MARK A. SMITH. Attest:

W. M. BLAKEY, RoB'r. W. HARPER. 

